Respiration Flashcards iGCSE Biology

[q] What is Anaerobic respiration?

[a] The chemical reactions in cells that break down nutrient molecules to release energy without using oxygen is called Anaerobic respiration.

• The release of a relatively small amount of energy;
• By the breakdown of glucose;
• In the absence of oxygen / without oxygen;

[q] Anaerobic respiration

[a]

• Occurs when oxygen is not present. 
• Incomplete breakdown of glucose
• Less efficient than aerobic respiration and produces less energy per glucose molecule. 
• Occurs in the cell cytoplasm and thus does not require mitochondria.

[q] How can we measure gas given off a aquatic plant?

[a]

• Measure volume
  • Use inverted test-tube / measuring cylinder / syringe (barrel) ;
  • reference to, graduations / markings ; A ‘take readings from…’ / ‘record results…’ filled with water ;
  • gas collects at the top and pushes out the water / downward displacement of water;
  • gas syringe ;
    • attached by (delivery) tube to, flask / AW ;
• data logger for any other suitable electronic method ;
• reference to equilibration / described ;
• reference to time period ; A rate = volume divided by time

[q] State the balanced chemical equation for aerobic respiration 

[a] C₆H₁₂O₆ + 6O₂ → 6CO₂+ 6H₂O

+ 2830 kJ

[q] State the balanced chemical equation for anaerobic respiration in the microorganism yeast

[a] C₆H₁₂O₆ → 2C₂H₅OH + 2CO2

+ 118 kJ

[q] What are the uses of energy in the body of humans? (State atleast 5/7)

[a]

• Muscle contraction, Protein synthesis, Cell division, Active transport, Growth, The passage of nerve impulses, The maintenance of a constant body temperature.